Temperature regulating system



March 9, 1954 c D|CKE 2,671,881

TEMPERATURE REGULATING SYSTEM Filed July 30, 1949 l HEAT POSITION NOHEATHPOSITION TO CHECK DAMPER l INVENTOR. c424 H. 0/009 am p PatentedMar. 9, 1954 UNITED STATES PATENT OFFICE TEMPERATURE REGULATIN G SYSTEMCarl H. Dicke, New Bremen, Ohio, assignor to Crown Controls Company,Inc., New Bremen, Ohio, a corporation of Ohio Application July 30, 1949,Serial No. 107,683

11 Claims. 1

This invention relates to an improved temperature regulating system andmore particularly to such a device for use in connection with theregulation of dampers for heating furnaces.

An "object of the invention is to provide a simple and reliablemechanism which will assure that upon the occurrence of electric powerfailures the damper or other heat supply controlling mechanism will beadjusted automatically to reduced heat condition.

A further object is to provide an energy storing device such as a weightor spring which will upon the occurrence of power failures and aconsequent de-energization of the electric mechanism cause the dampercontrolling mechanism to return to normal no heaposition.

Another object is to provide such a device in which the dampercontrolling motor will in normal operation move in a forward directionfrom "heat to no heat position whereas upon the occurrence of powerfailures the motion from the no heat position will occur reversely.

Another object is to provide such a device including an electric motorhaving a plurality of operating coils, two being illustrated, arrangedin parallel together with means "for'so controlling the supply ofcurrent thereto that both coils are energized during the operation fromthe no heat to the heat position and means for energizing only one ofsaid coils when the parts have arrived at no heat position.

Another object is to provide such a device in which both coils areenergized during the major portion of the operation "from no hea to heatposition when power is on.

Further objects and advantages of the invention will be apparent fromconsideration of the specification as illustrated by the accompanyingdrawings of an illustrative embodiment of the invention, in whichdrawings:

Fig. 1 represents more .or less schematically one form the device maytake, the parts being shown in the heat position; and

Fig. 2 is aside elevation of the damper motor showing the position ofthe cranks in the fheat position.

Referring to said drawings, TI-I represents -,-generally a roomthermostat located in the space the temperature of which is to becontrolled and T represents the usual step-down transformer connected:to .the supply lines and delivering current at relatively low voltageto operate the mechanism.

The damper motor proper may consist-of housing H containing suitablebearings I-2 and the operating shaft 13, one end of which is carried 2 acrank [4 shown connected through a chain or the line [5 to the draftdamper l6 of the furnace to be controlled.

11 represents an energy storing device such as a weight or spring soconnected as to aid the closing of the draft damper. The crank I4 ispreferably so located on the shaft ['3 that it stands about from thevertical when the motor is in the heat position (see Fig. *2). Thepurpose of this is to make sure that the energy storing device iscapable of applying torque to the shaft I3 in the heat position.

When a check damper is also to be operated, it may be desirable toprovide also a crank 8 to which is connected a chain or the line isconnected to the check damper. The shaft [3 may be operated by the motorM through suitable reduction gearing (not shown), the gearing being suchas to rotate the shaft 13 in the direction indicated by the arrow inFig. 1.

Suitable circuit commutating means are provided which may take the formof a commutator such as the one shown, for example, "in my applicationfor United States Patent S. N. 654,052, filed March 1'3, 1946, nowPatent No. 2,548,424, dated April 1-0, 1951. Thus the shaft 13 may beprovided with a commutator sleeve having suitable openings therein suchas 21, "22, 23. The dotted rectangle represents a development of theexterior surface of such a commutator sleeve. The sleeve '20 is mountedupon an insulating tube '25 carried by the shaft l3 so that the tube andsleeve will rotate with said shaft. Mounted within the motor housing isan off brush and on brush 3] and operation completing brush 32 and aground brush 33 which is always in contact with the commutator sleeve'20. It will be noted that in the heat position shown, the "off brush isalso in contact with the sleeve'ZB. When the shaft I3 is in the no heatposition, the openings 22 and 23 will have moved to the "brush contactline so that in said position the on brush '3! is in contact with thecommutator sleeve.

The thermostat may, as usual, be comprised of a thermo responsiveelement 40 having ,a contact blade 4| which may, at times, engage oncontact 42, and, at other times, off contact 43.

The motor in the form shown consists of .a stator having four polepieces 46, 41, 48, and 49, each extending toward the rotor .50 which maybe of the well-known squirrel cage type. The pole .pieces 4649inclusive, are shown .provided with shading coils 46a, 41a, 48a, and 49arespectively. As shown, pole piece 46 is surrounded by coil 46b and pole48 is surrounded by coil 48b. The coil 4132) consists of finer wire ormore turns or both than coil 45?) so that it will draw less current thancoil 4612. One end of each of these coils is connected through conductorto one side of the secondary of transformer T. The side of coil 48b isconnected through conductor 52 with the "on contact 42 of the thermostatand through conductor 53 with on brush 3|. The other end of coil 46b isconnected through conductor 54 to the ground brush 33.. The other sideof the transformer secondary is connected through conductor 55 with thethermostat contact blade 4| and through conductor 56 with the "operationcompleting brush 32. The off contact 43 of the thermostat is connectedthrough conductor 51 with the "off brush 30.

It will be noted that in the heat position shown only coil 48b isenergized. The circuit is from the transformer through conductor 5|,coil 48b, conductor 52, on contact 42, blade 4| and conductor 55 back tothe transformer. The energization of coil 48a applies a forward torqueto rotor 50 which applies a clockwise torque to crank 4 as viewed inFig. 2. This torque is suflicient to prevent reverse rotation of crank|4 due to pull of weight l1 or a spring (if used) but is not sufficientto cause forward rotation. If, however, a power failure should occur atthis time (while the parts are in the "heat position) the motor would bede-energized and crank |4 would rotate counter-clockwise under theaction of the energy storing means until the crank l4 pointssubstantially downwardly thus leaving the draft damper closed and thecheck damper open. This is, of course, desirable to prevent overheatingof the heating plant during periods of power failure.

If, with the parts in the position shown, the thermostat should becomesatisfied so that the blade 4| moves from its on contact 42 to its "offcontact 43 (preferably by snap action), coil 48b will, at first bede-energized and 48b will be energized. The circuit through coil 45bwill be via conductor 5|, coil 46b, conductor 54, brush 33, commutatortube 20, brush 30, conductor 5|, off contact 43, blade 4|, bi-metal 40and conductor 55 ba .1 to the transformer. As coil 46b draws morecurrent there will be sufficient forward motor torque to rotate crank |4clockwise. After a slight forward rotation oi. crank l4 and commutatortube 20, brush 3| will engage the commutator. energize also the coil 48bto assist coil 46b. The circuit through coil 48b is via conductor 5|,coil 48b, conductors 52, 53, brush 3|, commutator 2!), brush 30,conductor 51, off contact 43, blade 4|, bi-metal 4|) and conductor 55back to the transformer. This operation will continue until the crank l4 and commutator 20 have moved a little more than one-half revolution,at which time brush 3|] will engage insulating material 22 and brush 32will engage insulating material 23, thus breaking the circuit from thetransformer to both coils 48b and 46b.

The parts are now in the no-heat position. If, now the temperature dropsso that thermostat blade 4| moves over to on contact 42, coil 46b willbe energized, the circuit being as follows: conductor 5| coil 46b,conductor 54, brush 33, commutator 20, brush 3|, conductor 53, contact42, blade 4|, bi-metal 40, and conductor 55 back to the transformer.Since coil 46b 1 5 1 6811 This will serve to 55 back to the transformer.

powerful to alone start the motor, the crank l4 will start to moveclockwise from its downwardly directed position. This will causeinsulating portions 22 and 23 to move away from under brushes 30 and 32so that they will engage the commutator 20. This will also cause coil 4%to be energized, the circuit being as follows: conductor 5|, coil 48b,conductors 52, 53, brush 3|, commutator 20, brush 32, conductors 56 andThis action will continue for about until the parts arrive at theposition shown in the drawings at which time coil 45b will becomede-energized and the motor will stop. However, coil 48b will remainenergized through the circuit described above and supply sumcientforward torque to prevent reverse motion of the crank l4, the gearingand the rotor 50 under the bias exerted by the weight I! or a spring, ifused. The parts will, therefore, remain in the on" position shown untila power failure occurs (in which case the crank I4 will rotatecounter-clockwise under the action of the energy storing means) or untilthe thermostat is satisfied and the blade 4| engages off contact 43 inwhich case the rotor and crank [4 will rotate forwardly as describedabove.

The reason for having only one winding (48!)? effective while the heatsupply control motor is in the "heat position and making that windingweaker than the other winding (46b) is that the control motor willfrequently stand in the heat position for long periods. As the electricmotor is stalled during these periods its efliciency is zero and all theelectric power delivered to it is converted into heat. The input wattagemust therefore be kept as low as possible to prevent overheating thewinding 48b and the bearings. During these periods the electric motoracts as 'a torque motor" as it may be stalled for long periods.

To simplify the disclosure, the energy storing, motor biasing means hasbeen shown as the weight W but it is to be understood that a returnspring may be preferred. In fact, the present invention is used inpractice with the construction shown and described in the application ofWilbert A. Will, Serial Number 94,314, filed May 20, 1949, now PatentNo. 2,613,543, dated October 14, 1952.

It is to be noted that the construction shown and described will serveadmirably to accomplish the objects stated above. It is to beunderstood, however, that the construction disclosed above is intendedmerely as illustrative of the invention and not as limiting as variousmodifications therein may be made without departing from the inventionas defined by a proper interpretation of the claims which follows.

I claim:

1. An electric motor for use in a heat supply control means for use in atemperature regulating system, the said electric motor having at leasttwo windings of different characteristics so that one draws suflicientcurrent to cause the motor to be rotated forwardly against a substantialload, whereas the other winding draws only sufli cient current to causethe electric motor to have the characteristics of a torque motor," andcircuit control means so arranged as to energize either, neither or bothof said windings.

2. In a temperature regulating system of the type including anelectrically operable heat supply control means adapted to control thesupply of heat to a space, a thermostat to be located in said space, andan electric power source, the

said heat supply control meansi-ncluding an electric motor having atleas't'two windings of different characteristics so that one drawssufficient current to cause the motor to be rotated forwardly whereasthe other winding draws sufficient current to develop only a smallforward torque, circuit means from said power source and connected tosaid thermostat and said electric motor, and commutator .means formingpart of said heat supply control means so arranged that when thethermostat moves to the fon position, the stronger of said windings isenergizod' to rotate the motor to the heat position but when the heatsupply control means has been moved to the heat" position, said strongerwinding will be de-energized and the weaker winding will be energized.

3. In a temperature regulating system of the type including anelectrically operable heat supply control means adapted to control thesupply of heat to a space, a single-pole, doublethrow thermostat to belocated in said space, said heat supply control means being of the typewhich has energy storing means connected to bias said means reverselyfrom its heat to its no heat position, and an electric power source, thesaid heat supply control means including an electric motor having atleast two windings of different characteristics so that one drawssufiicient current to cause the motor to be rotated forwardly, whereasthe other winding draws sufficient current to develop a forward torquewhich is not sufiicient to rotate the motor forwardly, circuit meansfrom a power source connected to said thermostat and said electricmotor, and commutator means forming part of said heat supply controllingmeans so arranged that when the thermostat moves to the on" position,the stronger of said windings is energized but when the heat supplycontrol means has been moved to the heat position, said stronger windingwill be de-energized and the weaker winding will be energized.

4. In a temperature regulating system of the type including anelectrically operable heat supply control means adapted to control thesupply of heat to a space, a thermostat to be located in said space, andan electric power source, the said heat supply control means includingan electric motor having at least two windings of differentcharacteristics so that one draws suificient current to cause the motorto be rotated forwardly against a substantial load whereas the otherwinding draws only sufficient current to cause the electric motor tohave the characteristics of a torque motor, circuit means including saidpower source, thermostat and electric motor, and commutator meansforming part of said heat supply controlling means so arranged that whenthe thermostat moves to the on position, the stronger of said windingsis energized but when the heat supply control means has been moved tothe heat position, said stronger winding will be deenergized and theweaker winding will be energized so that the electric motor willfunction as a torque motor.

5. A control apparatus of the class described, comprising incombination, a rotary operator, means for biasing said operator toward apredetermined position, rotary electric motor means coupled to saidopeator for moving said operator away from the position to which it isbiased against its biasing means, said motor being provided with alow-wattage and a high-wattage energizing *coil, means to first energizethe highwattage coil and then both coils whereby the motorrendered'operative to move said operator away from'its biased positionand means to then tie-energize said high-wattage coil to maintain saidopera-tor in such new position while the motor is stalled.

6. A control apparatus of the class described, comprising incombination, a rotary operator, means for biasing said operator toward apredetermined position, rotary electric motor means coupled to saidoperator for moving said operator away'from the psition to which it isbiased against its biasing means, said motor being provided withalow-wattageand a high watta'ge energizing coil, means to first energizethe high-wattage coil and than both coils whereby the motor is renderedoperative to move said operator away from its biased position, means tothen de-energize said high-wattage coil to maintain said operator insuch new position while the motor is stalled and means for then firstenergizing the high-wattage coil and then both coils whereby the motoris rendered operative to move said operator forwardly to the position towhich it is biased.

'7. A control apparatus of the class described, comprising incombination, a rotary operator, means for biasing said operator toward apredetermined position comprising a crank and an energy storing deviceconnected to said crank, rotary electric motor means coupled to saidoperator for moving said crank away from the position to which it isbiased against the bias exerted by said energy storing device, saidmotor being provided with a low-wattage and a high-wattage energizingcoil, means to first energize the high-wattage coil and then both coilswhereby the motor is rendered operative to move said crank away from itsbiased position and means to then de-energize said high-wattage coil tomaintain said crank in such new position while the motor is stalled.

8. A control apparatus of the class described, comprising incombination, a rotary operator, means for biasing said operator toward apredetermined position comprising a crank and an energy storing deviceconnected to said crank, rotary electric motor means coupled to saidoperator for moving said crank away from the position to which is biasedagainst the bias exerted by said energy storing device, said motor beingprovided with a low-wattage and a high-wattage energizing coil, means tofirst energize the high-wattage coil and then both coils whereby themotor is rendered operative to move said crank away from its biasedposition, means to then de-energize said high-wattage coil to maintainsaid crank in such new position while the motor is stalled and means forthen first energizing the high-wattage coil and then both coils wherebythe motor is rendered operative to move said crank forwardly to theposition to which it is biased.

9. A control apparatus of the class described, including an operatingmember, means for biasing said operating member in one direction, arotary electric motor for moving said operating member in the oppositedirection, said motor having two different coils one weaker than theother, an electrical control circuit for said motor including a switchadjustable to close a circuit through the relatively stronger one ofsaid coils, and commutator means operated by operation of said motoracting in response to an initial rotation of said motor to close acircuit through the weaker one of said coils and in response to apredeter- 7 mined further rotation of said motor to open the circuitthrough the stronger one of said coils.

10. A control apparatus according to claim 9, characterized in thatsaidswitch has alternating positions of adjustment in moving toeach of 5which said switch opens the circuit through the weaker one of said coilsand closes the circuit through the stronger one of said coils.

11. A control apparatus according to claim 10, characterized in thatsaid commutator means has successive positions of adjustment to which itis moved by said motor in the alternate positions of said switch, saidmeans tending in one of said positions to maintain the circuit openthrough the stronger one of said coils and to maintain the circuitclosed through the weaker one of said 8 A circuits, and tending in theother one of said positions to maintain the circuit open through bothsaid coils.

CARL H. DICKE.

References Cited in the flle of this patent UNITED STATES PATENTS CriseApr. 4, 1950

